8 
Description of Mr. South’s 
those which bind the different parts of a watch-chain toge- 
ther. At the third juncture the clamping takes place ; a pro- 
jecting part of the ring having been left where the third 
section is made, and a strong screw at right angles to this 
section, which is made to gape, brings the parts towards 
each other, and effects a firm embrace. The clamping appa- 
ratus, so far described, was avowedly borrowed from the 
means used for fixing the shaft of an ordinary wind-mill. 
To the middle of each of the trisected rings are fastened long 
arms of tinned iron plate, at the extremities of which the 
slow moving screws have their places. The fixed stud is in 
the lower screw planted in the iron support; that of the 
upper one in the polar axis ; the moveable studs are of course 
connected with the levers. 
The long screw for slow motion in right ascension is acted 
on by a contrate wheel and a pinion at right angles to the 
plane of the circle ; a long handle attached to it is shown in 
Plate I, fig. 1 , leaning against the northern pier. A similar 
screw for declination, but without the contrate part, is seen 
in Plate II, fig. 3. All the apparatus for clamping and slow 
motion is seen in Plates I, II, and III, figures 1, 3, and 3. 
It may be remarked, that in the apparatus described, the 
right-ascension motion does not at all disturb that in declina- 
tion ; nor does that of declination affect the other : properties 
most essential to facilitate and render accurate, micrometrical 
observations ; properties not to be expected, with the same 
precision, from those contrivances to which micrometers are 
usually attached, known by the name of equatorial stands. 
The illumination of the wires of the telescope is produced 
by a small lantern, which has its place at one end of the 
